1. Field of the Invention
The present invention relates to a suction apparatus equipped with an ejector, which is capable of attracting a workpiece under suction by a negative-pressure fluid, and of transporting the workpiece to a predetermined location.
2. Description of the Related Art
Recently, vacuum suction apparatus have widely been used for transporting and positioning thin-plate workpieces. Such a vacuum suction apparatus is equipped with a main body into which a compressed fluid is supplied, and a suction pad that is fixed to the main body. Compressed fluid, which is supplied to the main body, creates a negative pressure state in the interior of the suction pad that is in contact with a workpiece to thereby retain the workpiece, and the workpiece is positioned in a desired location, or is transported to the desired location, and next, the vacuum state is released by supplying compressed air or atmospheric air to the suction pad, whereby the workpiece separates from the suction pad and is placed at the desired location.
As this type of vacuum suction apparatus, with the vacuum assembly disclosed in U.S. Patent Application Publication No. 2008/0202602 A1, legs are disposed mutually in parallel in the vicinity of both ends of an elongate positioning mechanism, with valve assemblies being mounted respectively on the legs. Each of the valve assemblies includes a vacuum circuit having a suction cup installed on the end thereof. Compressed air is supplied to the suction cups from an air pressure line, whereupon suction conveyance of workpieces is carried out by maintaining a negative pressure (vacuum) condition in the interior of the suction cups.